HLA-DQ5#DQB1*0502
{{cs1 config|name-list-style=vanc}}
{{Infobox heteroisoform
| isoformgroup = HLA-DQ5
| polymer_type = MHC Class II, DQ cell surface antigen
| image = DQ Illustration.PNG
| image_source = Illustration of HLA-DQ with gliadin peptide in the binding pocket.
| isoformCount = 3
| subunit1 = DQA1
| subunit2 = DQB1
| isoform1 = DQ α1.1β5.1
| nick1 = DQ5.1
| allele1a = {{HQAA|0101}}
| allele1b = *0501
| isoform2 = DQ α1.2β5.2
| nick2 = DQ5.2
| allele2a = {{HQAA|0102}}
| allele2b = *0502
| isoform3 = DQ α1.4β5.3
| nick3 = DQ5.3
| allele3a = {{HQAA|0104}}
| allele3b = *0503
| isoform4 = DQ α1.2β5.4
| nick4 = DQ5.4
| allele4a = *0102
| allele4b = *0504
}}
HLA-DQ5 (DQ5) is a human leukocyte antigen serotype subgroup within HLA-DQ(DQ) serotypes. The serotype is determined by the antibody recognition of β5.x subset of DQ β-chains. The β-chain of DQ is encoded by HLA-DQB1 locus and DQ5 are encoded by the HLA-DQB1{{color|DarkGreen|*05}} allele group. This group currently contains 4 common alleles, DQB1{{color|DarkGreen|*0501}}, {{color|DarkGreen|*0502}}, {{color|DarkGreen|*0503}}, and {{color|DarkGreen|*0504}}. HLA-DQ5 and HLA-DQB1*05 are almost synonymous in meaning. DQ5 β-chains combine with α-chains, encoded by genetically linked HLA-DQA1 alleles, to form the cis-haplotype isoforms. These isoforms, are all HLA-DQ1 encoded by the DQA1{{color|DarkOrchid|*01}} allele group.
Serology
| border="0" align="left" cellspacing="0" cellpadding="0" style="text-align:center; background:#ffffff; margin-right: 2em; border:2px #e0e0ff solid;"
|+ DQ5, DQ1, and DQ6 recognition | ||||
| style="background:#f0f0ff"
| style="width:60px" | DQB1* | style="width:60px" | DQ5
| style="width:60px" | DQ1 | style="width:60px" | {{color|red|DQ6}} | style="width:60px" | Sample | |
| style="background:#f0f0ff"
| allele | % | % | % | size (N) |
| style="background:#e8e8f8" | {{HQBA|0501}} | 69 | 20 | {{color|red|2}} | 5536 |
| style="background:#e8e8f8" | {{HQBA|0502}} | 48 | 24 | {{color|red|15}} | 919 |
| style="background:#e8e8f8" | {{HQBA|0503}} | 58 | 22 | {{color|red|4}} | 1327 |
| style="background:#e8e8f8" | {{HQBA|0504}} | 59 | 17 | {{color|red|2}} | 48 |
| colspan = 5 style="font-size:smaller" | {{color|red|Red indicates the level of 'false' reaction in non-DQ5 serotypes}} |
The efficiency of DQ1 recognition relative to DQ5 and DQ6 is listed above. Since
DQ1 recognizes alpha, the DQ5 and DQ6 recognition are to beta chain. Meaning
that DQ1 is corecognized with DQ5 and DQ6. Efficient recognition of a genotyped allele approaches 100%. Compared to DQ2 serotyping of DQB1*0201 positive individuals (98%), the efficiency of DQ5 recognition is relatively low and error prone.
While DQ5 recognizes DQB1*05 alleles more efficiently than DQ1, the serotyping is rather poor method of typing for transplantation or disease association prediction or study.
Disease associations
=By serotype=
DQ5 is negatively associated with (protective against) idiopathic nephrotic syndrome in Polish children,{{cite journal |vauthors=Krasowska-Kwiecień A, Sancewicz-Pach K, Moczulska A | title = Idiopathic nephrotic syndrome in Polish children - its variants and associations with HLA | journal = Pediatr. Nephrol. | volume = 21 | issue = 12 | pages = 1837–46 | year = 2006 | pmid = 16967287 | doi = 10.1007/s00467-006-0271-7| s2cid = 23739129 }} and adrenocortical failure (Addison's disease).{{cite journal |vauthors=Myhre AG, Undlien DE, Løvås K, etal | title = Autoimmune adrenocortical failure in Norway autoantibodies and human leukocyte antigen class II associations related to clinical features | journal = J. Clin. Endocrinol. Metab. | volume = 87 | issue = 2 | pages = 618–23 | year = 2002 | pmid = 11836294 | doi =10.1210/jc.87.2.618 | doi-access = free }}
A study on the relationship between HLA-DR, DQ antigen, and intracranial aneurysm in the Han nationality show DQ5 more likely,{{cite journal |vauthors=Wang JF, Zhang D, Zhao JZ, Jia BX, Bi RM | title = A study on the relationship between HLA-DR, DQ antigen, and intracranial aneurysm in the Han nationality | journal = Surgical Neurology | volume = 66 | pages = S25–8; discussion S28–9 | year = 2006 | issue = Suppl 1 | pmid = 16904993 | doi = 10.1016/j.surneu.2006.06.048}} AIDP type of Guillain Barré syndrome,{{cite journal |vauthors=Guo L, Wang W, Li C, Liu R, Wang G | title = [The association between HLA typing and different subtypes of Guillain Barré syndrome] | language = zh | journal = Zhonghua Nei Ke Za Zhi | volume = 41 | issue = 6 | pages = 381–3 | year = 2002 | pmid = 12137599 }} and irritable bowel disease {{cite journal |vauthors=Trachtenberg EA, Yang H, Hayes E, etal | title = HLA class II haplotype associations with inflammatory bowel disease in Jewish (Ashkenazi) and non-Jewish caucasian populations | journal = Hum. Immunol. | volume = 61 | issue = 3 | pages = 326–33 | year = 2000 | pmid = 10689124 | doi =10.1016/S0198-8859(99)00134-2 | pmc = 4524574 }} but not crohn's disease in the same (Jewish) population. Other studies show DQ5 is associated with extra-intestinal manifestations of Crohn's.{{cite journal |vauthors=Hesresbach D, Alizadeh M, Bretagne JF, etal | title = Investigation of the association of major histocompatibility complex genes, including HLA class I, class II and TAP genes, with clinical forms of Crohn's disease | journal = Eur. J. Immunogenet. | volume = 23 | issue = 2 | pages = 141–51 | year = 1996 | pmid = 8732477 | doi =10.1111/j.1744-313X.1996.tb00275.x | s2cid = 32885468 }}
DQ5 is shown to be associated with increased risk of gastric mucosal atrophy in Helicobacter pylori infected subjects.{{cite journal| author=Beales IL, Davey NJ, Pusey CD, Lechler RI, Calam J| title=Long-term sequelae of Helicobacter pylori gastritis. | journal=Lancet | year= 1995 | volume= 346 | issue= 8971 | pages= 381–2 | pmid=7623555 | doi=10.1016/s0140-6736(95)92263-6 | pmc= | s2cid=12603873 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7623555 }}
DQ5 appears to be associated with analgesic intolerance.{{cite journal |vauthors=Kalyoncu AF, Karakaya G, Yilmaz E, Balci B, Karaduman A, Yasavul U | title = Analgesic intolerance with or without bronchial asthma: is there a marker? | journal = Journal of Investigational Allergology and Clinical Immunology | volume = 13 | issue = 3 | pages = 162–9 | year = 2003 | pmid = 14635465 }}
=By haplotype=
MuSK antibody-positive myasthenia gravis HLA-DR14-DQ5,{{cite journal |vauthors=Niks EH, Kuks JB, Roep BO, etal | title = Strong association of MuSK antibody-positive myasthenia gravis and HLA-DR14-DQ5 | journal = Neurology | volume = 66 | issue = 11 | pages = 1772–4 | year = 2006 | pmid = 16769963 | doi = 10.1212/01.wnl.0000218159.79769.5c| s2cid = 41206495 }} probably DRB1{{color|Brown|*1402}} : DQA1{{color|DarkOrchid|*0104}} : DQB1{{color|DarkGreen|*0503}} (DR14-DQ5). DR1-DQ5 is associated with sensitivity to acid anhydrides.{{cite journal |vauthors=Jones MG, Nielsen J, Welch J, etal | title = Association of HLA-DQ5 and HLA-DR1 with sensitization to organic acid anhydrides | journal = Clin. Exp. Allergy | volume = 34 | issue = 5 | pages = 812–6 | year = 2004 | pmid = 15144476 | doi = 10.1111/j.1365-2222.2004.1956.x| s2cid = 7864063 }}